Crossfading between 2 audio signals / single supply opamp circuit

I suggest you using such a circuit as below. first section is a inverting unity gain op-amp. then a voltage divider. and finally a voltage subtract circuit.

Vou = Input2 + (Input1/K)

which K is the constant of pot R3.

Advantages of this circuit :

1. No Loading effect on the both input voltages.
2. Control Gain of each Input voltage independently.

^{simulate this circuit – Schematic created using CircuitLab}

There are simpler circuits like this one: -

And I've posted it for two reasons, 1) to show the decoupling capacitors that must be fitted and 2) to explain that your circuit has certain benefits that may not be that obvious.

You circuit does not rely on the signal sources being low impedance - if the pot is totally at one end of its travel it will 100% attenuate one signal whereas the simplified circuit won't do that if the output impedances of the signal sources are not zero.

If you are expecting unity gain, then you ought to figure out the proper value of feedback resistor - with your circuit's pot at one end, the other channel will suffer a fair amount of attenuation but this can be easily remedied however you need to state what value your pot has. I'd go for your circuit over my example.

The basic idea is OK, but the DC biasing is messed up. The DC level of R3 should be decoupled from the opamp input.